Circuit-controller.



E. .I. MURPHY.

CIRCUIT CONTROLLER.

APPLICATION FILED JUNE 28, 1912.

Patented Sept. 21, 1915.

WZTNESSES M. (0

UNITED srATEs PA TENT ornion.

EDWIN J. MURPHY, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CIRCUIT-CONTROLLER.

Specification of Letters Patent.

Patented Sept. 21, 1915.

Application filed June 28,1912. Serial No. 706,362.

cient manner.

My invention relates more specifically to circuit controllers of the type which are given a step by step movement by electromagnetic operationl In controllers of this character it has heretofore, been customary to provide an operating mechanism in which the movable member is provided with ratchet teeth adapted to be engaged by a movable pawl. One common construction is to have the controlling member secured to a rotatable disk, the periphery of which is provided with teeth adapted to be engaged by a ,will move with it.

pawl which is electromagnetically operated. This ratchet arrangement, while satisfactory under certain conditions, is opento the objection that the ratchet teeth and the pawl wear outrapidly especially when the service is severe. Moreover, the cutting of the teeth on the disk is expensive, since the material must be hard to resist wear.

In carrying out my invention I provide a step by step mechanism in which the pawl and ratchet action is replaced by magnetic attraction. In the case of a rotary disk the periphery is smooth and of magnetic material and the reciprocating member magnetically grips the disk in the operating direction and returns free of the disk. A solenoid is preferably employed as the operating means and'the reciprocating core of the solenoid is preferably so mounted adjacent the periphery that when the solenoid is energized its core will engage the periphery of the disk and as the core is moved the disk When the solenoid is deenergized the core will drop back freeof the disk. The arrangement of the parts is such that a magnetic circuit is formed which is almost entirely closed through iron, a por tion of the disk being included in the magnetic circuit.

Other objects and purposes of my invention' w1ll appear in the course of the followng specification in which I have shown my invention embodied in concrete form for purposes of illustration.

Referring to the drawing it will be seen that I have shown my invention embodied.

in a controller for electric motors. It is obvlous, however, that my invention is in no sense limited to this particular type of controller but is equally applicable to any cir= cuit controlling device.

In the drawing, 10 represents a controlling arm cooperating with a plurality of studs 11 and 12 connected with resistances 13- and 14 respectively. These studs are arranged concentrically, as shown, and are adapted to be engaged successively by the arm 10. This controlling arm is rotated in either direction by rotating the wheel or disk 15 which is secured to the arm. The periphery of this disk is made of magnetic material and for purposes of illustration I have shown a wheel of cast iron having a thick rim. For operating this disk in opposite directions I have provided two electromagnetic devices 16 and 16. These two devices are identical in construction and operation and it will therefore be sufiicient to describe the construction of one of them.

The .device 16 consists of a solenoid 17 provided with a core 18 having a projection 19 of magnetic material. at its lower end which extends into proximity with. the periphery of the disk 15, The'solenoid and core are preferably vertically arranged so that when the core is raised by the solenoid it will'drop back by gravity when the solenoid is deenergized. The core is preferably loosely mounted in the solenoid and the projection on the core extends so near to the periphery of the wheel that a very slight lateral motion of the core will enable the projection 19 to engage the periphery of the disk15 and move away from it to a slight extent. This lateral play of the core may be reduced until it is hardly noticeable, the principal requirement being that the projection will drop free of the disk. At the upper end of the solenoid is a bar of magnetic material 20 which is cut away at 21 to receive the core and extends across the top of the disk 15. For simplicity of construction the bar extends all the way across to the device 16 so as to form a part of'the magnetic circuit of both devices al.-

though it is not essential that the two portions on each side of the center be integral with each other. 21 so as to partially inclose the disk but is separated from the periphery of the disk by the small air gap 21. The lefthand portion of the bar 20 therefore forms a portion of the magnetic circuit of which the core 18 and theperiphery of the disk form the other portions. The right hand-portion performs a similar function in the device 16. This makes a very efficient structure and concentrates the lines of force soas to afford a maximum pull upon the core. order to make the operation of the electromagnetic device automatic I provide a switch for controlling the circuit of the solenoid consisting of a stationary contact 23 and a movable contact '22. 'Thesta to and insulated 20 while the movable contact troller as arranged to control an electric tionary contact is secured from the bar is secured to the end of an arm 24 pivoted at 25, connection being made ;with'.' the arm provided at switch arm through the flexibleconnection The switch arm is operated bythe core which has at its upper end arod 26 extendingthrough 27 so as to give solenoid is deenergized the weight of the core will move the contact '22 down into o l-"- gagement with the contact 23 assshown in drawing.v As the'core rises itengages;

the the vertically moving plunger 28'; passing through the bar 20, thehead of which will engagetheswitch arm and open the contacts. In order to prevent vibration of the contacts and make the action: c ertain and at the same time give a snap action to the permanent magnet 29' switch I provide a which is arranged to engage the free end of the switch arm 24. In the. particular arrangement I have shown the -magnet 29 bent in the form illustrated so as to act tacts to cause sparking, sm'cejas soon as the end of the arm *24 gc'onies into proximity sufiiciently to et 29 it will be attracted and 7 held flth'ereby l avoiding any vibration .ofthe switc e ontacts Likewise when the-core-l8 rises an d-liftsthe' switch arm 24 through the ag ncy of the plunger 28, the. magnet will" holcl'theswitch arm ive it 'a 'certainamount of snap action. norder to damp the move- This bar is cut away at moves away from the an opening in the switch its upper end with nuts. the core a lost motion coir" nection withthe switch arm. When the I provide abrake consisting of a shoe 32 set in an opening in the bar 20 and held in contact with the periphery of the'disk by a spring 33. This spring is located in a socket 34 in the block 30 and surrounds the stem 35 extending up through the block. The braking-action of this shoe will be sufficient to insure that the disk will'move only so .far as it is moved by the electromag netic device and will not be carried beyond this point by the momentum of the parts. In order to automatically stop the movement of the device near the limit of travel,

I provide limit switches 36 and 37 pivoted at 38 and 39, respectively, adapted to be opened by engagement with a pin 40 on the under side of the disk. These switches are normally closedso that-as soon as the pin switch the latter will close. i I

.As' above stated, I have shown. the conmotor having an armature A and a shunt field F. The armature-is connected with a segment 41 which is concentric with the studs 11 and 12 and is coextensive, with --the' two sets of studs.

I The. field F is connected to the segment 42 concentric with the segment 41 and co-extensive with the studs 11. Another segment 43 is connectedwith the negative side of theline and is co-ext" nsi-ve with the segment 41, while segment 44fis connected .with the studs 11 at one end andconnected with the negative side of the line at the other. The controlling arm-10 .is' provided with two bridging contacts as shown in ,dotted lines, the one at the outer end 45: being arranged to bridge the studs 11 and segment 44 with segment 41 while the inner contact 46 bridges the segment 42 and studs 12 'with the segment 43. The switch S .provided with two contacts 47 and 48 is arranged to close the circuit for any direction of rotation.

As thus constructed and arranged the operation of my device will be as follows: Assuming the parts to be in the position shown in the drawing, when the switch S is moved into en agement with the contact 47 the solenoid-l will be energized through conductor 49, contacts 22 and 23, limit switch 37, back to the negative side of the line. When the solenoid 17 is energized the magnetic circuit will be through the core 18, projection 19, through the rim of disk 15, through the gap 21' and the left hand portion of bar 20, and back to the core. This will cause the projection 19 to magnetically ip the periphery of the disk 15 and as t e core 18 is lifted the disk will be rotated. When the core strikes the plunger 28, the switch contacts 22 and 23 will be opened with a snap will be clear of the periphery of the disk 15 on the return movement. The dropping back of the core causes the contacts to be closed and the permanent magnet 29 prevents the chattering of the contacts. The core 18 will reciprocate up and down, stepping the disk 15 in a clockwise direction until the pin 40 engages the limit switch 3'? in a clockwise direction cutting the resist ance 13 out of the armature circuit and then cutting the resistance 14 into the field circuit of the motor. is reached the pin 40 engages the' limit switch 37 and opens the circuit of the solenoid 17. When the switch S is moved into engagement with the contact 48 the electromagnetic device 16 will be operated to turn noid. It will be seen that with this arrangement a step bystep movement is given to the control member in -'a positive manner without the use of ratchet teeth and pawls.

The magnetic circuit is such as to make the device very eflicient and afford a maximum embodied in concrete form and as operating in a specific manner in accordance with the patent statutes, it should be understood that .I do not limit my invention thereto, since adjacent thereto for rotating the same in opposite directions,.a magnetic element in close proximity to the member and formlng part When the final position of the magnetic circuit of said devices, a reciprocating core for each device included in the magnetic circuit with the adjacent portions of the magnetic element and member so as to magnetically grip the member and move the same when the winding with which it is associated is energized. 2. A controlling device for electric circuits comprising a rotary member of mag-Q netic material, electromagnetic devices on opposite sides thereof for moving the same in each direction, a bar of magnetic material extending between the two devices'in close proximity to the member to form a part of the magnetic circuit of said devices, two reciprocating cores one for each electromagnetic device included in the magnetic circuit with the adjacent portions of the bar and member so'as to magnetically grip the member and rotate the same when the magnet is energized, and a switch associated with each core for controlling the electromagnetic device.

3. Acontroller for electric circuits comprising a rotary member of magnetic ma; terial, electromagnetic devices on diametrically opposite sides thereof for rotating the same in opposite directions, a bar of magnetic material extending between the two devices in close proximity to the member to form a part of the magnetic circuit of said devices, a reciprocating core for each device included in the magnetic circuit with the adjacent portions of the bar and member so as to magnetically grip the member and rotate the same when the winding of the device with which it is associated is ener gized.

In witness whereof, I have hereunto set my hand this 26th dayof June, 1912.

- EDWIN J. MURPHY.

Witnesses:

BENJAMIN B. HILL, HELEN ORFORD. 

